Security officials in Pakistan say a powerful bomb has ripped through a police compound in the country's largest city, Karachi, killing at least 15 people and wounding 100 others. The Pakistani Taliban have claimed responsibility for the attack.

Police in Karachi say a group of militants opened fire on the Crime Investigation Department compound before detonating a massive car bomb. The explosion destroyed much of the police building, damaged nearby houses and left a large crater in the road.

The blast occurred in a high-security area of Karachi that is home to the U.S. Consulate, luxury hotels and the offices of government leaders.

The Crime Investigation Department takes the lead in hunting down terrorists in Karachi and is used as a detention center for criminals.

Ahmed Chanai directs the Citizen Police Liaison Committee, a privately established group designed to create good will between police and the citizens of Karachi.

"This was a soft target," Chanai said. "The terrorists were able to come to the second gate of the building and then they blew themselves up and made a very, very big impact around the whole city. In fact, half of the city heard this blast. There has been a panic situation in the whole city."

Karachi is Pakistan's economic capital and home to nearly 16-million people, the country's stock exchange, and a port on the Arabian Sea.

Pakistan is battling Islamist militants with links to the Taliban and al-Qaida, who have bombed government, police and Western targets in recent years.

Afzal Shigri is the former police chief of Sindh Province, where Karachi is located.

"We are in a state of war, in this war against terrorism," Shigri said. "These are the kinds of situations, these are the kinds of incidents for which we have to be prepared. And having said that, we also have to look at it, where are the gaps, where are the weaknesses."

Pakistan says thousands of people have been killed in suicide attacks and bombings blamed on extremist networks since the country joined the U.S.-led war on terror.